This invention relates to a mast collar system. It relates more particularly to an improved sealing joint construction between a mast and a boat deck.
A mast collar is a fitting that is engaged around the mast at the point where the mast projects down through the boat deck. The purpose of the collar is to fill the gap between the mast and the edge of the deck opening and to provide a watertight joint or gasket between the mast and the deck. Also mast collars include means for swivelly attaching blocks to accommodate the various lines running down the mast. Conventionally, the collar is exactly what the name implies, simply a flanged ring which engages around the mast at the point where the mast projects through the boat deck with the ring flange being screwed to the deck. Sometimes a resilient gasket is disposed between the ring and the mast to provide a more effective watertight seal at the joint.
Prior mast collar constructions of this general type have not been entirely satisfactory. This is because as the mast flexes when the boat is under sail, the gasketing material is forced or works itself out of the space between the collar and the mast leaving a gap through which water can enter and drip down into the interior of the boat hull causing damage to interior woodwork, fixtures and the like.
Some attempts have been made to avoid this problem by providing redundant gasketing and mast collars with very high tolerances. However, these attempts have proven to be expensive and have not entirely eliminated the leakage problem.